1. Field of the Invention
The present invention relates to a Land Grid Array (“LGA”) connector and a package mount structure for conduction between an LGA package and a system board.
2. Description of the Related Art
Systems for conduction between a package and a system board include a ball grid array (BGA) system in which a package is soldered directly to a board and a land grid array (LGA) connector system. The BGA system has the problems of heat generated at connection and the time and cost for replacement, while the LGA connector system needs only works at room temperature and facilitates replacement because of a configuration to provide conduction by pressure.
FIG. 1 shows a package mount structure of a related art (in sectional view). FIG. 2 shows the package mount structure of the related art (in plan view).
The package mount structure has a configuration in which a heatsink base 52, a lid or heat spreader 53, and a bolster plate 57 are pressed by tightening them with screws 58 with a spring 59. Principally, the outer four corners of an LGA package 54 are pressed to clamp an LGA connector 51 between a package board 55 that mounts the LGA package 54 and a system board 56.
The LGA connector 51 is pressed with the screws 58 at the four corners to collapse columns 61 of the LGA connector 51, so that the electrodes of the package board 55 and the system board 56, and a silver filler among the columns 61 are brought into conduction, thereby providing conduction between the LGA package 54 and the system board 56.
The LGA connector 51 is sandwiched between the heatsink base 52 and the bolster plate 57, and the outer four corners of the LGA package 54 are pressed with screws. Accordingly, the load on the columns 61 is not even, i.e., the load on the outer side adjacent to the four corners is large, and the load on the inside is small.
Since a socket 62 of the LGA connector 51 is made of a low-rigidity resin material such as polyimide in the present circumstances, it is deformed under a load to cause unevenness in load on the columns 61.
Since the LGA connector 51 is screwed at four portions in sequence and pressed with the springs 59 at assembling, it is difficult to provide sufficient parallelism.
For these reasons, if the load imposed on some of the columns 61 is low, there is a possibility of nonconduction.